| 摘要 |
<p>A pulse width modulated three-phase inverter is disclosed which controls the harmonic content in the output waveforms by utilizing notches created by the addition of eight extra switching points in the inverter cycle. The notches, which are symmetrically crated about four locations in the cycle, vary in width to control the amplitude of the fundamental frequency component of the output wave form, while the angles which are the centers of the notches create a unique relationship between the fundamental frequency component and the fifth and seventh harmonics. the resulting waveforms permit variable frequency, constant volts/Hertz operation of an AC induction motor drive system without increasing the percentages of fifth and seventh harmonics while varying the fundamental frequency of the system.</p> |
